mbndenhall



2 Sheets-Sheet 2.

A. MENDENHALL.

Calculating Machine.

Patented Aug. -13, 1867.

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A. MNDENH A L'li, OF CERRO GORDO, INDIANA.

Laim Parmi No. 67,786, ma August 13, 1867.

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TO ALL WHOM IT MAYA7 CONCERN:

Be it known that I, MENDENHALL, of Cerro Gordo, Randolph county, Indiana, have invented a. new and improved Calculating Machine; and I ldo hereby declare that the following is a full, clear. andexactV description thereof, which willenable others skilled in the art to make and use the same, reference being had tothe accompanying drawirgs, forming part of this specification. i

The object of this invention consists in constructing a machine by which figures of any desired magnitude may be readily added, subtracted, multiplied, and divided.

`Figure 1, sheet 1, represents a plan of my improved calculating machine.

Figure 2, sheet l, a sectional side elevation of the same, parts being broken away' to show construction.

Figure v3, sheet 2, a plan of the same, with the top plate removed ;l and `Figure 4, sheet 2, is a side elevation of the same.A

Similar letters of. reference indicate corresponding parts.

This calculating machine consists of a, square metal b'ox, a; with a boss in the centre of the same inside, in which the shaft ofthe cylinder b is to turn; and c is a graduated plate on top of the cylinder b, which is keyed tothe said cylinder, and will revolve with the same. d is a fixed graduated plate, which lits over the graduated ange of the plate c, and is provided with a spaceor slot, d, in its inner edge, through which to read the iumbers on the pla-te c be,neath.

. In the accompanying drawings is given a sample of part of the table to be used. The table is to be a multiplication table, of which each figure from I to 100 inclusive is te be both a multipl'icand and a. multiplier, arranged in the order of the sample shown in the drawings. Figures I 2 3 4 5 6 7 8 9 10, seen on the cover, shall be extended to 100, embracing cach intermediate number, and each row of holes en ei'ther side of the saidligures, and parallel therewith, shall be extended to 100 also. These holes will bear the following denominations, as indicated by the following letters, U H T, and 'at the left-hand margin C, which denotes cents, U units, H hundredths, and T thousandths of units, and these may be extended to any desired magnitude. On another sido of the box will be seen three rows of holes on t-lie lid or cover d, which numerate in the following he inside row next the figures on the lid denotes units, the nexthundredths, and the last or outside row .ndths of units, and these may be extended to any desired denomination.

- Example.

I Place the engraved hand e opposite the opening Vin the lid, then take the pin and place it in the hole in the e of the wheel c opposite figure 95, and turn to the left -until the pin stops against the -hand and 95 will seen through the opening in the lid. New place the pin at figure 40, and turn tothe left as before, and 35 l be seen through the opening in the lid; the 40 and 95 being added together make 135. In this operation tddition it is seen that the engraved hand on the wheel c has passed the opening in the lid d, which shows in i process of Aoperation a. pin, which should be placed in the hole denominated as hundreds, and opposite figure 1 the lid. Now place the pin in the wheel at 90, and turn to the left as before, and 25 will be seen, and the raved hand has passed the openinga'ga-in.. Now move the pin in the lid opposite ligure 2, which denotes i`=225. New subtract T0, by turning the wheelback until the pin is opposite gure 70 on the lid, and re the pin in tho lid opposite 2 back to I, and we have the answer 155. By this method the operator does carrying and borrowing in addition and subtraction.

Iwill now proceed toshow how the machine performs the operation independent of the operator. The face'of a. small wheel, g, is seen on the side ofthe box first examined. This shall be provided with everything similar to the wheel c, heretofore described, except the holes on the lid. On turning the cylinder around, a pin, h', is seen, which projects, and serves to work the small wheel gjust spoken of, which is divided into onehundred grooves or teeth `on its inner side, and the angle of these grooves or teeth is to be just Asuiiicient to allo wheel gto be turned one tooth for cach revolution of the cylinder.

I will now proceed to show an example in multiplication and division. Multiply 5 by 3. The cylinder is urned so 'that figure 3 is seen at the right-hand margin of the cylinder; a pin is placed at 5 inthe hole of units, .d 15 will be seen opposite 5 on the cylinder, which is the product. Again the pin is moved to4 the hole of w the BEST AVAILABLE Coe ames v 2 eds, and the twoiciphers 0 0 at theright hand are considered added to the rightvof the 15, and we have 1,500. If the pin ismoved to thousands the three cipliers O 0 0 are considered added, andv we have 0,000. And if the multiplier 3 is supposed to be 300, n pin is also placed opposite 3 on the lid, and in the second hole, and the two oiphe'r's there to b'e added as before If the 3 is to be considered 3,000 the pin will be placed in theYthir-d hole, and the three cipliers added to the right of the product.

In working division wie will consider the product in multiplication to be the. dividend, the multiplier aso divisor, and the multiplicand as a. lquotient, ciphers considered as before. l

I do notwish to limit myself to the size or shape of this machine; nor uo I limit myself` to constructing it of brass, as it may be made of wood, card-board, or any other suitable material. l i

Having thus described my invention, I claim as new, and desire to secure by Letters Patent- A The combination of the box a, graduated cylinder b, graduated wheel c, fixed graduated plate @slotted and graduated plate formingtlxe end of the box a, small grooved wheel o, pin 'h' in the cylinder b, and'thc arm f, all constructed and arranged to operate es hel-'ein set forth for the purpose specified.

A. MENDENHALL. Vitnesses:

JOHN W. Bor'rUN, F. A. ENGLE. 

